Amazon.com Inc. has added another benefit to its Prime two-day shipping program. Prime members now have access to unlimited photo storage in Amazon Cloud Drive, the e-retailer’s online data storage service.

“This time of year in particular, families are capturing thousands of photos of holiday parties, family gatherings and opening presents,” says Greg Greeley, vice president of Amazon Prime. “With free unlimited photo storage, we’re providing one more reason for members to use Prime every day. Prime has always allowed members to conveniently save time and save money, and now with Prime Photos they can save memories too.”

Prime membership, which costs $99 per year, includes free two-day shipping on more than 20 million items, instant streaming of thousands of movies and TV episodes through Prime Instant Video, 1 million songs through Prime Music, early access to select Lightning Deals and access to more than 600,000 books to borrow through the Kindle Owners’ Lending Library.

The photo storage service is the third time in recent months that Amazon has tweaked its Prime program. In October, Amazon added a referral program that gives consumers a $5 Amazon credit if they sign up a friend. In late July, Amazon launched a “no-rush” shipping option for Prime members. In return for a bit of patience—instead of getting their goods within two days, customers will receive orders in five to seven business days—Amazon will reward those customers with a $1 credit that can be applied to titles offered by Amazon Instant Video.

Amazon is No. 1 in the Internet Retailer Top 500 Guide.